1. Field of the Invention
The present invention relates to a camera system capable of automatic focus control in response to focus detection through an objective lens.
2. Description of the Prior Art
In this field of art there has been disclosed a camera having a focus sensing device responsive to a light transmitted through the objective lens, means for generating a driving power for automatic focus control in response to the focus sensing device, and means for detecting a condition for stopping the generation of the driving power to stop the generation of the driving power on the condition. For example, such a condition corresponds to an in-focus condition, or a condition in which the focus adjustment is brought to one end of its adjustable range before the desired focus adjustment has been completed.
With respect to the stopping of the generation of the driving power in the in-focus condition, there has been known to finish the generation of the driving power when the in-focus condition is detected, and to fix the focus adjustment for a shot. In this manner of automatic focus adjustment, however, there is a problem in that the shot would result in a misadjustment of focus if the in-focus condition is erroneously detected. According to another type of automatic focus adjustment in which the generation of the driving power is intermitted during the time the in-focus condition is being detected for making the focus adjustment automatically follow the change between in-focus and out-of-focus conditions, the quickness of the focus adjustment would be insufficient or an unsteady focus adjustment would be caused.
On the other hand, in stopping the generation of the driving power at one end of the possible focus adjustable range it has been desired to avoid any possibility that the focus adjustment would erroneously lock at the end of the adjustable range in spite of any fact that the focus adjustment should be properly made within its adjustable range.